1. Field of the Invention
The present invention relates generally to the field of devices and methods for installing geothermal closed loops in the ground.
2. Description of the Prior Art
Geothermal heating and cooling systems operate by exchanging heat between the constant temperature ground and a heat exchange medium circulated in a tube extending through the ground. In order to cool a building, heat within the building flows into the coolant medium within the tube extending from the building and through ground. The reverse is true when heating a building wherein heat from the ground flows into the coolant medium which is then circulated via the tube in the building with the heat flowing from the coolant tube into the building.
In an open loop system, existing ground water is used as the heat exchange medium which flows through the tube. The water may be obtained from a well, pond or lake or water located beneath ground.
In a closed loop system, the tube or pipe holding the heat exchange medium may be arranged in horizontal loops placed four to six feet below ground and installed using a backhoe along the length of each loop. A considerable amount of land is required to accommodate a horizontal system. Conventional boring machines allow the bored hole to extend downward into the ground and then upwardly exiting the ground at a distance located a great distance from the entrance to the hole. Once the drill head exits the hole, the heat exchange tube is mounted to the drill head and pulled back through the hole. To create a hole that extends downward and then horizontally and then upwardly requires a great horizontal distance due to the limitations of the boring machine. Alternatively, the tubes carrying the heat exchange medium may extend vertically for hundreds of feet below ground and installed by a well digging rig.
In the case of utilizing the above described open loop systems or closed loop systems, well digging machines, backhoes, and boring devices are brought onto the land for boring of the holes resulting in considerable damage to the turf and landscape. In many cases, the size of the lot may not allow sufficient room for the use of all of the equipment to create the holes. Further, the holes may extend horizontally such a great distance so as to extend beyond the boundary of the lot. On residential property landscaped prior to installation of a geothermal system, the resultant expense and mess caused by the hole boring machine presents a significant drawback to the installation of the geothermal system.
Disclosed herein is a device and method for installing a u-shaped tube into a single hole thereby minimizing the destruction to the landscape while also providing for a quicker installation minimizing the construction cost. Further, a small pit roughly five feet in width, length, and depth is created with the hole being bored at the bottom of the pit allowing the water, dirt, etc. to move upwardly from the bored hole into the pit. Once the u-shaped coolant tube is installed, the material may then flow from the pit into the hole thereby surrounding the tube and improving the heat transfer between the tube and the ground. A particular advantage results since the pit limits the amount of damage to the landscaped ground by containing the material from the boring process.